To determine how much of a conventional lamp’s raw lumen output reaches a task area, you must discount any light lost in the fixture housing (often over 30%), as well as any light lost as a result of lensing, shading, and filtering. Since incandescent and fluorescent lamps emit light in all directions, you must further discount any light emitted in a direction away from the target area.
Evergreen LED lighting products are integrated systems in which the light sources (LEDs), the fixture housing, and the primary optics are inseparable. Lumen measurements of LED lighting fixtures, therefore, are performed on the entire system, and already account for light lost to the fixture housing and lensing. Furthermore, since LEDs are inherently directional, they emit almost all of their light output in the desired direction, rather than dispersing it in all directions. And since LEDs natively produce intensely saturated colored light, they require no gels or filters which can block a significant percentage of a fixture’s light output (over 90% for certain shades of deep blue).
When comparing lighting fixtures on the basis of delivered light, Evergreen LED luminaries often perform as well, and in some cases significantly better, than conventional fixtures, while consuming far less energy.